Increasing attention is being given to monitoring the pressure of tires on a vehicle while the vehicle is in motion. A typical wireless tire pressure monitoring (TPM) system includes a transmitter circuit coupled to each of a plurality of tires on a vehicle. Each transmitter circuit includes a tire pressure sensor inserted into a tire and a radio frequency transmitter. The transmitter circuits sense tire pressure and generate radio frequency signals. The tire pressure monitor system includes a tire pressure monitor comprising a receiver circuit for receiving and demodulating the radio frequency signals. The receiver circuit monitors the signals by, for example, reading the tire pressure data, displaying the tire pressures of each tire, providing a warning when a tire pressure is outside predetermined parameters, etc.
Recently, many companies are producing transmitter circuits for tire pressure monitoring systems, each with its own data protocol. Each data protocol includes different encoding patterns, modulation schemes, bit timing, etc. Therefore, an original equipment manufacturer must purchase a tire pressure monitor from the same company that sells the corresponding transmitter circuits, which is a disadvantage. Further, when replacing a tire on a Vehicle, the tire transmitter must be matched with the receiver, requiring the maintenance of a large database of information regarding which transmitters are compatible with which tire pressure monitors for which vehicles. Since new tires are replaced repeatedly throughout the life of the vehicle, this problem is compounded.
One prior system includes a tire air pressure monitoring and reporting system having a multiple frequency receiver display unit. The receiver display unit receives radio signals from wheel transmitters and, through the use of an internally mounted conventional scanning receiver, allows for the activation of tire indicator lights on the front of the display unit. The indicator lights indicate the abnormal status of each respective tire on the motor vehicle independently. One drawback of this receiver display unit is that it is not configured to receive messages having different protocols.
Accordingly, what is needed is an improved tire monitoring system and method for monitoring tire characteristics, such as tire pressure, temperature, etc. Further, what is needed is a tire monitoring system and method for receiving data messages having different protocols. Further still, what is needed is a tire pressure monitoring system and method for receiving and monitoring wireless radio frequency signals from a plurality of vehicle tires, wherein the tire pressure data is transmitted according to different wireless data protocols. The teachings hereinbelow extend to those embodiments which fall within the scope of the appended claims, regardless of whether they accomplish one or more of the above-mentioned needs.
According to an exemplary embodiment, a tire monitor for monitoring a characteristic of tires on a vehicle includes a circuit configured to receive a first wireless signal having tire characteristic data in a first wireless protocol. The circuit is further configured to receive a second wireless signal having tire characteristic data in a second wireless protocol. The second wireless protocol is different than the first wireless protocol. The circuit is further configured to monitor first tire data on the first wireless signal and second tire data on the second wireless signal.
According to another exemplary embodiment, a tire pressure monitor for monitoring tire pressure on a plurality of tires on a vehicle includes a receiver circuit and a control circuit. Each tire includes a wireless transmitter for transmitting tire pressure data wirelessly. At least one of the wireless transmitters utilizes a different wireless protocol than another of the wireless transmitters. The receiver circuit is configured to receive wireless signals from the plurality of tires. The control circuit is configured to receive the wireless signals from the receiver circuit, to identify the wireless protocols of the wireless signals and to monitor tire pressure data on the wireless signals.
According to yet another exemplary embodiment, a method of monitoring tire characteristics for a plurality of tires on a vehicle includes receiving tire characteristic data messages having different protocols and monitoring tire characteristic data on the tire characteristic data messages.
According to still another exemplary embodiment, a system for monitoring tire characteristics for a plurality of tires on a vehicle includes means for receiving tire characteristic data messages having different protocols, and means for monitoring tire characteristic data on the tire characteristic data messages.